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[en] Different kinds of detectors for the measurement of x-ray position, intensity, and sample responses have been introduced. Basically x-ray generated photoelectrons, ions and electrons from gas molecules, and electron-hole pairs inside semiconducting devices are monitored by electronics as signal. Since better performing detectors can provide better statistics and liability of the experimental data, lots of efforts on the realization of better detectors are still being made in the synchrotron radiation community.
[en] In this study, a new technique to plot the isodose curves and Percentage Depth Dose (PDD) that are used to test the validity of miniature x-ray tube is developed using MATLAB code. The results are in good agreement with already published data in publically accessed literature. Recommendations and systematic studies regarding relative dosimetry for kilovoltage x-ray beams are lacking in literature. The variation in the relative dose response were found to be very low. The measurement of percentage depth dose data (PDD) for the beam qualities studied with an uncertainty of about 3%.
[en] There are two methods of scanning cargoes; inspecting the cargoes with opening by hand, and without opening using the X-ray. Especially, the scanning method using X-ray has been mainly used for smuggling monitoring because it can search cargoes quickly, and its use is expanding at present. Since the practical cargo scanner is expensive to operate, the developed simulator is worth using. This simulator can be used as a test and feedback before starting the practical cargo scanner. And system optimization and material identification through dual X-ray energy will be done in further works.
[en] The 3D printer whose method is Digital Light Processing (DLP) was used to make plastic scintillators in an innovatively short time (20 minutes to 2 hours). Three kinds of acrylic monomers were used in the fabrication to see the effect on the detector performance depending on the monomer material. In this study, three types of tests were carried out. The light output relative to that of BC408 commercial plastic scintillator was estimated and compared. The highest light output was 45.2% for Sample 11. As a next task, we will investigate the performance of scintillators based on non-acrylic monomers fabricated by 3D printer.
[en] In this paper, the nitriding kinetics and mechanism were quantitatively analyzed by the new proposed analysis methods: the mass balance analysis and the optical microscope image processing analysis. Using these combined methods, the mass gain curves and the optical microscopes are analyzed in very detail, and the mechanisms of nitriding accelerated, stabilized and saturated behaviors were well understood.
[en] One of the major shift in nuclear safety system since Fukushima Daiichi accident is adopting, in Vienna Declaration, “practical elimination of large/early releases from NPPs” as one of implementation principle. The concept of “practical elimination” first introduced in 1999 as safety target for new reactors has now become something necessary to demonstrate after international community experienced Fukushima accident. In Europe where it has already been adopted as a safety target for new reactors, practical elimination is expected to be a regular topic for heated debates.
[en] In this study, the effect of normalizing temperature on mechanical property and microstructures of 9Cr-1Mo martensitic ODS steel was investigated. It was shown that the microhardness was steadily increased with increasing of the normalizing temperature. According to TEM observation, mechanical property of 9Cr-1Mo ODS steel was significantly affected by lath width. These observations, could be useful to understand the relationship between normalizing temperature and microstructure.
[en] Korea Multi-purpose Accelerator Complex (KOMAC) has several ion accelerators to provide various ion beams to users. A test stand of ion source is being developed to satisfy the needs from the users for the applications with kV range ion beam implantation. A 100 MHz RF ion source has being installed and tested with bias voltages to check its characteristics. The ions are basically extracted by the potential differences in the entire system. Therefore, ion beam extraction conditions are affected by probe, deck and focus bias voltage. We check the bias effects for extracting ions
[en] Two-fluid equations are the basic and the only model for the two-phase flow analysis in nuclear reactor systems. In this study, the modified Reynolds stress model is validated. The experiment of Kocamustafaogullari was tested for the validation. Throughout the investigation, the present modification can correct the velocity distribution to make the upper part slower the lower part. Therefore, the modified model is reasonably recommended to be used in analyzing bubbly flows.
[en] The public debate over the use of nuclear energy is not limited to the area of technology, and has become subject to the public's subjective perceptions and emotions regarding the issue. This study empirically demonstrated the advantage of loss framing in improving public's favorable responses toward nuclear energy messages. Such framing effect was found to be moderated by individuals' daily use of online news. The findings of this study suggest that public's cognitive and emotional responses toward nuclear messages should be carefully considered when planning effective nuclear communication program.